1. Field of the Invention
This invention relates generally to railway cars and, more particularly, to a railway car of the open gondola type having a drop center in which the lading is loaded and unloaded from the open top of the car.
2. Description of the Prior Art
Gondola railway cars, which are open at the top, are normally employed to carry bulky granular materials such as coal, sand and gravel. Some gondola cars have a continuous center sill structure extending the length of the car and a flat floor plate on the top of the center sill. The floor plate is supported by the cross bearers which, in turn, are supported by the side structure. This structure results in a high center of gravity in the loaded car.
A variation on this conventional car is shown in U.S. Pat. No. 3,713,400 to Teoli. This type of car, known as a Teoli car in the railcar industry, has a parabolic shaped bottom between the trucks and no continuous center sill. The center sill is replaced by draft sills, or stub sills, at each end. The draft sills extend from the ends to the parabolic shaped tub portion. The draft sills are connected with the side sills at each end by separate shear plates which transfer the longitudinal forces to the sides of the car. The side structure then transmits the load along the length of the car.
A similar gondola railway car is disclosed in U.S. Pat. No. 3,240,168 to Charles. The Charles patent shows a gondola railway car with the dropped bottom between the trucks reinforced by spaced apart lateral ribs. The Charles car lacks a center sill between the rail trucks.
The various components of gondola cars are specifically designed to support and distribute the longitudinal and vertical forces of the load and the forces of leading and trailing cars. These forces are distributed to the side panels and vertical or end panels. The forces are also distributed to the draft sills and side sills as well as other support members.
One area which receives a particularly high concentration of the loading is the shear plate, or flat floor portion. The railcar is pulled in the longitudinal direction along the draft sills by the leading car and the trailing car. The load along the draft sills is reacted by the shear plate which is attached to the top of the draft sills. The load is transferred by the shear plate to the side sills and down the length of the car. The vertical distance between the longitudinal load on the draft sill and the longitudinal reaction on the shear plate creates a moment arm or torque coupling of the longitudinal forces. Despite the small moment arm distance between the two forces, the large longitudinal forces can result in an extremely powerful moment or torque coupling.
While the inside of the gondola car is utilized for structural support, it is also designed for easy removal of the granular loads of gondola cars. For example, the end panels typically include a curved portion at their bottoms in order to keep the granular material out of the corners of the inside car body. The curved bottom of the end panel, while facilitating the holding of the granular material, provides an inadequate structure to withstand the fatigue loadings encountered by the railcar during travel.
The gondola railway car of the present invention provides increased strengthening of the railcar to better support the various loadings and stresses placed on the railcar. The improved car provides support brackets to counteract the moment created by the longitudinal force on the draft sill and the reaction force on the shear plate. The improved car also includes the addition of gussets at four intersections of the side panels with the shear plate. Several other strengthening improvements are provided, including a top corner cap and the repositioning of the vertical reinforcement members.